1. Field of the Invention
The present invention relates to a brushless DC motor.
2. Description of the Related Art
There is conventionally known a brushless DC motor including a rotor formed by attaching permanent magnets to the outer circumferential surface of a cylindrical yoke member with an adhesive agent or the like and a stator arranged to surround the outer circumference of the rotor (see, e.g., Japanese Patent Application Publication No. 2002-034188). In such a motor, the respective permanent magnets are magnetized with an N pole or an S pole and the N-pole-magnetized permanent magnets and the S-pole-magnetized permanent magnets are alternately arranged in the circumferential direction of the rotor. A brushless DC motor is typically provided with a position detecting sensor for detecting the position of a rotor. In a conventional brushless DC motor disclosed in, e.g., Japanese Patent Application Publication No. 2005-124368, three Hall integrated circuits (ICs) are arranged radially outward of a rotor as position detecting sensors. The rotating position of the rotor is detected using the magnetic flux waveforms detected by the respective Hall ICs.